Re: change attnum in pg_catalog.pg_attribute - Mailing list pgsql-general

From Tom Lane
Subject Re: change attnum in pg_catalog.pg_attribute
Date
Msg-id 26417.1112726492@sss.pgh.pa.us
Whole thread Raw
In response to Re: change attnum in pg_catalog.pg_attribute  (Grzegorz Przeździecki<Grzegorz.Przezdziecki@PolskieSklepy.pl>)
Responses Re: change attnum in pg_catalog.pg_attribute  (Grzegorz Przeździecki<Grzegorz.Przezdziecki@PolskieSklepy.pl>)
List pgsql-general
Grzegorz =?iso-8859-2?q?Prze=BCdziecki?= <Grzegorz.Przezdziecki@PolskieSklepy.pl> writes:
>> It won't work and will likely crash the backend.

> Even if I will do like this  and for ever??

> 1. attnum will be unique and greater than 0
> 2. no holes in attnum numeric
> 3. Make change
> 4. restart postgresql

Yes, unless you also TRUNCATE the table, because attnum ordering tells
about the physical data layout within the table rows.  Furthermore,
altering only pg_attribute is unlikely to represent a complete update
of the catalogs --- attnums also show up in pg_index, pg_attrdef,
pg_depend, pg_rewrite if there are any rules or views mentioning the
columns, and probably some other places I forgot.

            regards, tom lane

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